Devices for stabilizing clavicle bones that have been fractured are well known in the art and stabilize the broken bone by providing an axial load force which keeps the fractured ends of the bone in contact with each other. Referring to FIG. 1, these IM fixation devices typically include anchoring threads disposed on an anterior portion of the IM fixation device and a bone re-association system disposed on a posterior portion of the IM fixation device, wherein the bone re-association system includes a threaded portion and a stabilizing nut. Axial re-association of the fractured portions of the bone is achieved by threading the IM fixation device through both portions of the fractured clavicle bone such that the anterior portion of the IM device is disposed within the IM region of the anterior portion of the fractured clavicle bone. The anchoring threads disposed on the anterior portion of the IM device engage the IM region of the anterior portion of the fractured clavicle bone to snugly contain the IM fixation device within the bone.
The posterior portion of known IM fixation devices are often movably disposed within the IM region of the posterior portion of a fractured clavicle bone such that the bone re-association system is protruding from the posterior lateral end of the clavicle bone. The stabilizing nut is rotated to engage the threaded portion of the IM fixation device, thus causing the stabilizing nut to partially traverse the threaded portion of the IM fixation device. As the stabilizing nut traverses the threaded portion, the stabilizing nut pushes the posterior portion of the fractured clavicle bone toward the anterior portion of the fractured clavicle bone. The stabilizing nut is rotated until the anterior and posterior portions of the fractured clavicle bone contact each other, such that the fractured ends of the clavicle bone remain in contact with each other to allow for the accelerated healing of the clavicle fracture.
Unfortunately, existing IM fixation devices have a number of disadvantages associated with them that adversely affect the healing and comfort of the patient. The profile of the bone re-association system prominently protrudes from the posterior lateral end of the clavicle bone. The patient will experience extreme discomfort as even the smallest movement causes pain in the fascia tissue. Further, current IM fixation device designs do not provide torsional resistance to bone fragments. In situations where torsional support can not be provided by bone fragment interstices, current IM fixation device designs allow the fracture surfaces to grind or rub together, compromising the healing process and causing pain.